1. Field of Invention
The invention relates to an image quality analysis system and method that can perform any of a series of specific image quality analyses based on one or more test patterns to perform evaluation of printer and copier image quality automatically.
2. Description of Related Art
It is well known that customer satisfaction can be improved and maintenance costs reduced if problems with copiers and printers can be fixed before they become serious enough to warrant a service call by the customer. While current technology exists to enable printers and copiers to call for service automatically when sensors detect certain operating parameters outside of permissible ranges, there is not a very comprehensive manner of detecting incipient system failure or automatically diagnosing when problems with image quality reach a level where human observers perceive a reduction in quality. This is caused not only by the large number of operating parameters that would need to be tracked, but also because these parameters are strongly coupled to one another. That is, a given parameter at a certain value may or may not be a problem depending on the values of other parameters. While existing systems provide some level of image quality analysis, these systems have been found less than satisfactory as image quality determination is machine dependent and may be inconsistent with perceptions of image quality as judged by human users.
There is a need for image output devices, such as printers and copiers, to better self-diagnose problems relating to image quality. Applicants have found that to comprehensively and reliably measure the system performance of a printer or copier, the image quality of the output must be measured.
There also is a need for an image quality analysis system that can determine various aspects of image quality easily and with minimal user involvement and minimal user expertise. An automated image analysis system for printed output should ideally be able to handle an arbitrary test pattern without the need of human assistance to specify which test pattern or analysis sequence should be performed.
According to one aspect of the systems and method of the invention, these problems are solved by allowing the analysis to be controlled by a script, which in turn is selected based on information contained in an identifying label or marker that is decoded from a scan of a printed test sample. The identification label is preferably part of the digital input test pattern, and is in human-readable and/or machine-readable form. Besides assistance in controlling what analyses are to be performed, such a label can also be used to identify a particular machine that is being tested, and provide other relevant information.
Systems which can perform image analysis on printed test samples can be used in a variety of ways to provide solutions and value to users of digital printers and copiers, for example, as the analysis engine for automatic or remote diagnosis of print quality problems, or for monitoring image quality as part of a print quality assurance system.
The system, according to an aspect of the invention, uses a scanner, either a stand-alone or part of a multi-function printer/scanner/copier, to scan the printed test sample, and then perform a series of analyses on the scanned image using an image quality analysis module that may be built into the image output device being tested, or provided as a stand-alone component that can receive the output from the scanner. There are often a number of different test patterns that would be used depending on which print quality issues are being tested. It is therefore necessary to provide information to the analysis system about which test pattern has been scanned, and which analysis should be performed. This information could be provided manually by an operator, but that significantly reduces the value of the automated analysis.